CN115557802A - Ceramic membrane and preparation method thereof - Google Patents

Abstract

The invention discloses a ceramic membrane, which comprises a metal oxide particle accumulation type ceramic membrane main body, wherein a carbon layer is attached to the surface of metal oxide particles, and carbon spheres are arranged in gaps among the metal oxide particles. The method takes the saccharides which are cheap and easy to obtain and have wide sources as raw materials to form the carbon layer on the surface of the metal oxide particles, so that the problem of poor stability in an acid solution is solved, and the carbon spheres in the gaps further optimize the pore size distribution range of the ceramic membrane so as to improve the performance of the ceramic membrane.

Description

Ceramic membrane and preparation method thereof

technical field

The invention belongs to the technical field of ceramic membrane preparation, in particular to an acid-resistant ceramic membrane and a preparation method thereof.

Background technique

Ceramic membrane is a kind of inorganic membrane. It is widely used in wastewater treatment, oil-water separation, food processing and pharmaceutical manufacturing, metal smelting and textile because of its advantages such as high mechanical strength, high temperature resistance and organic solvent, long life, and large processing capacity. Dyeing and other industries, many of which involve the treatment of acidic solutions, such as the recovery of industrial acidic waste extracts and acid-containing wastewater in the electroplating industry, the treatment of fermented acidic sewage, the purification of acidic juice, the purification and separation of drugs, mining and other processes.

Ceramic membranes usually use metal oxide powders such as alumina, zirconia, and titania as raw materials, and add additives such as binders and sintering aids. Particle-stacked separation membranes prepared by the method or atomic layer deposition technology. The pores of the porous separation membrane are voids formed by the accumulation of metal oxide particles. Metal oxide particles and additives in the preparation process are unstable when exposed to strong acidic solutions, or run in acidic solutions for a long time, and the microstructure of the pores, the properties of the inner walls of the pores, and the mechanical properties of the ceramic membrane are thus destroyed. Therefore, metal oxide particle-stacked ceramic membranes have the problem of poor stability in acidic solutions, which greatly limits the use of ceramic membranes. In addition, narrow pore size distribution is an important condition for such ceramic membranes to have good separation selectivity. However, the size of the voids formed by particle accumulation is not uniform, and there is still room for optimization of the pore size distribution of ceramic membranes.

The information disclosed in this Background section is only for enhancing the understanding of the general background of the present invention and should not be taken as an acknowledgment or any form of suggestion that the information constitutes the prior art that is already known to those skilled in the art.

Contents of the invention

The purpose of the present invention is therefore, the present invention adopts physical or chemical process to deposit the acid-resistant protective layer on the surface of the inner wall of the ceramic membrane channel, and fills the larger pores inside the ceramic membrane to optimize the pore size distribution, thereby overcoming the defects in the above-mentioned prior art, and can be obtained from Improve the performance of porous ceramic membranes in many ways.

In order to achieve the above object, the present invention provides a ceramic membrane, which includes a metal oxide particle accumulation type ceramic membrane main body, an acid-resistant carbon layer is attached to the surface of the metal oxide particles, and there are adjustments in the gaps between the metal oxide particles. Interstitial carbon spheres.

The present invention forms a carbon layer on the surface of metal oxide particles by using cheap, easy-to-obtain and widely sourced carbohydrates as raw materials, which solves the problem of poor stability in acidic solutions, and the carbon spheres in the gaps further optimize the pore size distribution range of the ceramic membrane , to improve its performance.

Preferably, in the above technical solution, the metal oxide particles are aluminum oxide, zirconium oxide, titanium oxide or other metal oxides suitable for preparing cermet membranes.

Preferably, in the above technical solution, the carbon layer is an enveloping carbon layer formed on the surface of the metal oxide particle after carbonization of the sugar substance.

A method for preparing a ceramic membrane as described above. The main body of the metal oxide particle-stacked ceramic membrane is fully soaked in a sugar solution, and the soaked ceramic membrane main body is hydrothermally reacted to obtain a carbon-coated ceramic membrane.

The hydrothermal reaction process refers to the general term for related chemical reactions in fluids such as water, aqueous solution or steam at a certain temperature and pressure.

Preferably, in the above technical solution, the sugar solution is an aqueous solution of sugar, and the concentration of the sugar solution is not lower than 36g/L.

Preferably, in the above technical solution, the sugar is monosaccharide, disaccharide, polysaccharide or other sugars capable of hydrothermal reaction to form carbon.

Preferably, in the above technical solution, the hydrothermal reaction time is not less than 4 hours, and the reaction temperature is not lower than 120°C.

Preferably, in the above technical solution, the reaction node of the hydrothermal reaction is: the ceramic membrane changes from white to brown or almost brown, and the reaction is stopped to obtain a carbon-coated ceramic membrane.

Preferably, in the above technical solution, the ceramic membrane is fully soaked in the sugar solution by means of immersion or hydraulic pressure.

Preferably, in the above technical solution, the carbon-coated ceramic membrane has a shell structure, and the shell structure is an enveloping carbon layer formed on the surface of the ceramic membrane matrix particles after carbonization of sugar substances in the sugar solution.

Preferably, in the above technical solution, the carbon-coated ceramic membrane is washed with water and ethanol until the eluate is colorless, and then dried. The role of the separation membrane is mainly divided into two types, one is concentration and the other is impurity removal. Generally, the membrane used for concentration permeates water molecules, so as to realize the concentration of the solution on the feed side, and finally collect the retained liquid; The membrane needs to prevent impurities from permeating, remove impurities, and finally collect the permeate. The products of the hydrothermal reaction may remain on the membrane pores and the surface of the carbon layer. If they are not cleaned, the membrane permeate will be polluted.

Compared with the prior art, the present invention has the following beneficial effects: Compared with the prior art, the present invention has the following beneficial effects: the present invention uses the aqueous solution of sugar as the raw material to carry out hydrothermal reaction, during which the sugar biomass is dehydrated and degraded , polycondensation, rearrangement and other reactions. In the early stage of the reaction, the small molecular substances generated in the reaction first combine with the hydroxyl groups on the surface of the metal oxide particles that constitute the ceramic film, realizing the attachment to the surface of the particles, and the hydrothermal products continue to intertwine in the subsequent reactions. Cohesion, adhesion, sedimentation, and finally a carbon layer is coated on the surface of the accumulated metal oxide particles, blocking the contact between acidic substances and metal oxides. At the same time, the carboxyl groups on the surface of the carbon layer further repel the approach of acidic substances; at the same time, the reaction The small molecules produced by dehydration and degradation in the medium form carbon spheres through polycondensation, nucleation, and mutual adhesion, filling the gaps where metal oxide particles accumulate, and optimizing the pore size distribution of the ceramic membrane. The separation channels of the carbon-coated ceramic membrane are still based on the gaps formed by the accumulation of metal oxide particles, and the carbon coating layer and carbon spheres modify the pores of the separation membrane. The characteristics of the invention are: 1. The acid resistance of the ceramic membrane is improved; 2. The pore size distribution of the ceramic membrane is optimized.

Description of drawings

Figure 1 shows the appearance of the ceramic film before and after carbon coating: (a) (b) (c) are the SEM and TEM results of the surface and section of the alumina ceramic film, respectively, (d) (e) (f) are SEM surface and cross-section and TEM results of carbon-coated alumina ceramic film.

Figure 2 Pore size distribution curve of ceramic membrane.

Figure 3 Mass loss of alumina ceramic membrane and carbon-coated alumina ceramic membrane.

detailed description

Specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations thereof such as "includes" or "includes" and the like will be understood to include the stated elements or constituents, and not Other elements or other components are not excluded.

Example 1

1 Experimental reagent: glucose (analytical pure, Sinopharm Chemical Reagent Co., Ltd.);

2 Experimental steps:

S1, the aqueous solution of glucose of preparation 36g/L;

S2. Make the alumina ceramic membrane (with a pore size of about 100 nm) fully soaked in the glucose solution by soaking or hydraulic pressure;

S3, carry out hydrothermal reaction, the reaction temperature is 120 ℃, the time is 4 hours, the surface of the ceramic membrane changes from white to brown, stop the reaction, and obtain a carbon-coated alumina ceramic membrane;

S4, cleaning the carbon-coated alumina ceramic film until the eluate is colorless, and drying.

Example 2

1 Experimental reagent: glucose (analytical pure, Sinopharm Chemical Reagent Co., Ltd.);

2 Experimental steps:

S1, the aqueous solution of glucose of preparation 36g/L;

S2. Make the alumina ceramic membrane (with a pore size of about 100 nm) fully soaked in the glucose solution by soaking or hydraulic pressure;

S3, carry out hydrothermal reaction, the reaction temperature is 200 ℃, the time is 14 hours, the surface of the ceramic membrane changes from white to brown, stop the reaction, and obtain a carbon-coated alumina ceramic membrane;

S4, cleaning the carbon-coated alumina ceramic film until the eluate is colorless, and drying.

Example 3

1 Experimental reagent: glucose (analytical pure, Sinopharm Chemical Reagent Co., Ltd.);

2 Experimental steps:

S1, preparing 90g/L aqueous glucose solution;

S2. Make the alumina ceramic membrane (with a pore size of about 100 nm) fully soaked in the glucose solution by soaking or hydraulic pressure;

S3, carry out a hydrothermal reaction, the reaction temperature is 180 ° C, the time is 8 hours, the surface of the ceramic film changes from white to brown, stop the reaction, and obtain a carbon-coated alumina ceramic film;

S4, cleaning the carbon-coated alumina ceramic film until the eluate is colorless, and drying.

Example 4

1 Experimental reagent: glucose (analytical pure, Sinopharm Chemical Reagent Co., Ltd.);

2 Experimental steps:

S1, preparing 145g/L glucose aqueous solution;

S2. Make the alumina ceramic membrane (with a pore size of about 100 nm) fully soaked in the glucose solution by soaking or hydraulic pressure;

S3, carry out a hydrothermal reaction, the reaction temperature is 180 ° C, the time is 8 hours, the surface of the ceramic film changes from white to brown, stop the reaction, and obtain a carbon-coated alumina ceramic film;

S4, cleaning the carbon-coated alumina ceramic film until the eluate is colorless, and drying.

Example 5

1 Experimental reagent: xylose (Shanghai Yuanye Biotechnology Co., Ltd.);

2 Experimental steps:

S1, preparing 90g/L xylose aqueous solution;

S2, adopt the mode of immersion or hydraulic pressure to make the aluminum oxide ceramic membrane (aperture about 100nm) fully infiltrate in the xylose solution;

S3, carry out hydrothermal reaction, the reaction temperature is 160 ℃, the time is 6 hours, the surface of the ceramic membrane changes from white to brown, and the reaction is stopped to obtain a carbon-coated alumina ceramic membrane;

S4, cleaning the carbon-coated alumina ceramic film until the eluate is colorless, and drying.

Example 6

1 Experimental reagent: fructose (Shanghai Yuanye Biotechnology Co., Ltd.);

2 Experimental steps:

S1, preparing 90g/L fructose aqueous solution;

S2, adopt the mode of immersion or hydraulic pressure to make the aluminum oxide ceramic membrane (aperture about 100nm) fully infiltrate in the fructose solution;

S3, carry out hydrothermal reaction, the reaction temperature is 160 ℃, the time is 6 hours, the surface of the ceramic membrane changes from white to brown, and the reaction is stopped to obtain a carbon-coated alumina ceramic membrane;

S4, cleaning the carbon-coated alumina ceramic film until the eluate is colorless, and drying.

Example 7

1 Experimental reagent: maltose (Shanghai Yuanye Biotechnology Co., Ltd.);

2 Experimental steps:

S1, preparing 90g/L maltose aqueous solution;

S2, adopt the mode of immersion or hydraulic pressure to make the aluminum oxide ceramic membrane (aperture about 100nm) fully infiltrate in the maltose solution;

S3, carry out hydrothermal reaction, the reaction temperature is 160 ℃, the time is 6 hours, the surface of the ceramic membrane changes from white to brown, and the reaction is stopped to obtain a carbon-coated alumina ceramic membrane;

S4, cleaning the carbon-coated alumina ceramic film until the eluate is colorless, and drying.

Example 8

1 Experimental reagent: sucrose (analytical pure, Sinopharm Chemical Reagent Co., Ltd.);

2 Experimental steps:

S1, preparing 90g/L sucrose aqueous solution;

S2, the alumina ceramic membrane (with a pore size of about 100 nm) is fully soaked in the sucrose solution by soaking or hydraulic pressure;

S3, carry out hydrothermal reaction, the reaction temperature is 160 ℃, the time is 6 hours, the surface of the ceramic membrane changes from white to brown, and the reaction is stopped to obtain a carbon-coated alumina ceramic membrane;

S4, cleaning the carbon-coated alumina ceramic film until the eluate is colorless, and drying.

Example 9

1 Experimental reagent: β-cyclodextrin (analytical grade, Sinopharm Chemical Reagent Co., Ltd.);

2 Experimental steps:

S1, boil and prepare 90g/L aqueous solution of β-cyclodextrin;

S2. Fully soak the aluminum oxide ceramic membrane (with a pore size of about 100 nm) in the β-cyclodextrin solution by soaking or hydraulic pressure;

S3, carry out hydrothermal reaction, the reaction temperature is 160 ℃, the time is 6 hours, the surface of the ceramic membrane changes from white to brown, stop the reaction, and obtain the carbon-coated alumina ceramic membrane;

S4, cleaning the carbon-coated alumina ceramic film until the eluate is colorless, and drying.

Example 10

1 Experimental reagent: dextran (Nantong Feiyu Biotechnology Co., Ltd.);

2 Experimental steps:

S1, preparing 90g/L dextran aqueous solution;

S2, adopt the mode of immersion or hydraulic pressure to make the aluminum oxide ceramic membrane (aperture about 100nm) fully infiltrate in the dextran solution;

S3, carry out hydrothermal reaction, the reaction temperature is 160 ℃, the time is 6 hours, the surface of the ceramic membrane changes from white to brown, stop the reaction, and obtain the carbon-coated alumina ceramic membrane;

Example 11

1 Experimental reagent: soluble starch (analytical pure, Sinopharm Chemical Reagent Co., Ltd.);

2 Experimental steps:

S1, boil the starch aqueous solution of preparation 90g/L;

S2, adopt the mode of immersion or hydraulic pressure to make the aluminum oxide ceramic membrane (aperture about 100nm) fully infiltrate in the starch solution;

S3, carry out hydrothermal reaction, the reaction temperature is 160 ℃, the time is 6 hours, the surface of the ceramic membrane changes from white to brown, stop the reaction, and obtain the carbon-coated alumina ceramic membrane;

S4, cleaning the carbon-coated alumina ceramic film until the eluate is colorless, and drying.

Example 12

1 Experimental reagent: glucose (analytical pure, Sinopharm Chemical Reagent Co., Ltd.);

2 experimental steps:

S1, preparing 90g/L aqueous glucose solution;

S2. Make the alumina ceramic membrane (with a pore size of about 800nm) fully soaked in the glucose solution by soaking or hydraulic pressure;

S3, carry out hydrothermal reaction, the reaction temperature is 180 ℃, the time is 8 hours, the surface of the ceramic membrane changes from white to brown, stop the reaction, take it out after cooling down naturally, and obtain a carbon-coated alumina ceramic membrane;

S4, cleaning the carbon-coated alumina ceramic film until the eluate is colorless, and drying.

Example 13

1 Experimental reagent: glucose (analytical pure, Sinopharm Chemical Reagent Co., Ltd.);

2 Experimental steps:

S1, preparing 90g/L aqueous glucose solution;

S2. Make the alumina ceramic membrane (with a pore size of about 3000nm) fully soaked in the glucose solution by soaking or hydraulic pressure;

S3, carry out hydrothermal reaction, the reaction temperature is 180 ℃, the time is 8 hours, the surface of the ceramic membrane changes from white to brown, stop the reaction, take it out after cooling down naturally, and obtain a carbon-coated alumina ceramic membrane;

S4, cleaning the carbon-coated alumina ceramic film until the eluate is colorless, and drying.

Example 14

1 Experimental reagent: glucose (analytical pure, Sinopharm Chemical Reagent Co., Ltd.);

2 experimental steps:

S1, preparing 90g/L aqueous glucose solution;

S2. Fully soak the zirconia ceramic membrane (about 400nm in aperture) in the glucose solution by soaking or hydraulic pressure;

S3, carry out hydrothermal reaction, the reaction temperature is 180 ℃, the time is 8 hours, the surface of the ceramic membrane changes from white to brown, stop the reaction, take it out after natural cooling, and obtain a carbon-coated zirconia ceramic membrane;

S4, cleaning the carbon-coated zirconia ceramic film until the eluate is colorless, and drying.

Comparative example 1: This comparative example provides an alumina ceramic membrane, which is washed with deionized water and dried.

Test example 1

1. SEM and TEM morphology

Field emission scanning electron microscopy and transmission electron microscopy were used to observe the morphology of the ceramic film respectively. The scanning electron microscope sample was sprayed with gold before use, and the transmission electron microscope sample was ground into powder before use and dispersed in ethanol. The ceramic film in the above-mentioned embodiment 3 and comparative example 1 Characterize the appearance.

2. Experimental instruments: Thermo Fisher QUANTA FEG 250 field emission scanning electron microscope, Hitachi H-7800 transmission electron microscope;

3. Experimental results:

It can be seen from Figure 1 that the ceramic membrane particles of the carbon-coated membrane are coated with an obvious carbon layer, and carbon spheres grow at the defect to optimize the pore size distribution.

Figure 1. The appearance of the ceramic membrane before and after carbon coating: (a) (b) (c) are the SEM and TEM results of the surface and section of the alumina ceramic membrane, respectively, (d) (e) (f) are SEM surface and cross-section and TEM results of carbon-coated alumina ceramic film.

Test example 2

1. Pore size distribution

Using mercury intrusion porosimetry, test the pore size distribution of the ceramic membrane in the above-mentioned embodiment 3 and comparative example 1

2. Experimental instrument: American Mike Pritic AutoPore IV 9510 mercury porosimeter;

3. Experimental results:

As can be seen from Table 1 and Figure 2, the pore size distribution of the alumina ceramic membrane is greater than 1%, and the corresponding pore diameter is concentrated in 40nm to 280nm. Compared with the alumina ceramic membrane, the pore size distribution of the carbon-coated alumina ceramic membrane prepared by the present invention The pore size corresponding to 1% is concentrated in 32nm to 150nm, indicating that the pore size uniformity of the carbon-coated alumina ceramic membrane is significantly improved.

The pore size distribution of table 1 ceramic membrane and carbon-coated alumina ceramic membrane;

Test example 3

1. Acid resistance test

The alumina ceramic membrane of Comparative Example 1 and the carbon-coated alumina ceramic membrane of Example 3 were subjected to an acid resistance test, and dilute hydrochloric acid and dilute acetic acid aqueous solutions were used as the acid resistance test solution, both of which had a pH of 3.77, and the above ceramic membrane was soaked The treatment lasts for 24 hours, the mass before and after the acid solution treatment is recorded, and the change of acid resistance is judged by the mass loss rate.

2. Experimental reagents: hydrochloric acid (analytical pure, Shanghai Lingfeng Chemical Reagent Co., Ltd.), acetic acid (analytical pure, Shanghai Lingfeng Chemical Reagent Co., Ltd.);

3. Experimental instruments: Sartorius PB-10 ion pH meter, Sartorius BSA224S-CW one-ten-thousandth balance;

4. Experimental results:

It can be seen from Table 2 and Figure 3 that the alumina ceramic membrane has obvious mass loss after acid treatment with dilute hydrochloric acid and dilute vinegar for 24 hours, while the mass loss of carbon-coated alumina ceramic membrane is significantly reduced after acid treatment.

The mass loss of table 2 alumina ceramic film and carbon-coated alumina ceramic film;

It can be seen from the results of the above test examples that the carbon-coated alumina ceramic membrane improves the uniformity of the pore size and improves the acid resistance, and is more suitable for the treatment of acidic solutions. .

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling others skilled in the art to make and use various exemplary embodiments of the invention, as well as various Choose and change. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims (10)

1. A ceramic membrane comprising a metal oxide particle-deposited ceramic membrane body, wherein an acid-resistant carbon layer is attached to the surface of the metal oxide particles, and carbon spheres for adjusting the gap are present in the gaps between the metal oxide particles.

2. The ceramic membrane of claim 1, wherein: the metal oxide particles are alumina, zirconia, titania or other metal oxides suitable for preparing metal ceramic membranes.

3. A ceramic membrane according to claim 1, wherein: the carbon layer is an encapsulated carbon layer formed on the surface of the metal oxide particle after the sugar substance is carbonized.

4. A method of preparing a ceramic membrane according to claim 1, wherein: and (3) placing the metal oxide particle accumulation type ceramic membrane main body in a sugar solution for 3 to 12 hours, fully soaking, and carrying out hydrothermal reaction on the soaked ceramic membrane main body to obtain the carbon-coated ceramic membrane.

5. A method for producing a ceramic membrane according to claim 4, wherein: the sugar solution is a sugar water solution, and the concentration of the sugar solution is not lower than 36g/L.

6. A method for producing a ceramic membrane according to claim 4 or 5, wherein: the sugar is monosaccharide, disaccharide, polysaccharide or other saccharides capable of hydrothermal reaction to carbon.

7. A method for the preparation of a ceramic membrane according to claim 4 or 5, wherein: the hydrothermal reaction time is not less than 4 hours, and the reaction temperature is not lower than 120 ℃; or the reaction node of the hydrothermal reaction is as follows: and (3) changing the ceramic membrane from white to brown or brown-like, and stopping the reaction to obtain the carbon-coated ceramic membrane.

8. A method for producing a ceramic membrane according to claim 4, wherein: the ceramic membrane is fully soaked in the sugar solution by adopting a soaking or hydraulic manner.

9. The method for producing a ceramic membrane according to claim 4, wherein: the carbon-coated ceramic membrane is of a shell structure, and the shell structure is an encapsulated carbon layer formed on the surface of ceramic membrane matrix particles after carbohydrates in a carbohydrate solution are carbonized.

10. The method for producing a ceramic membrane according to claim 4, wherein: and (3) cleaning the carbon-coated ceramic membrane with water and ethanol until the eluate is colorless, and drying.

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